In recent years, safety systems such as PCS (Pre-crash safety system) and the like are developed in order to avoid the collision or reduce the damage caused by the collision. In order to preferably realize such a safety system, it is necessary to correctly grasp, for example, the position and the size of an obstacle including, for example, a pedestrian and a vehicle other than a subject vehicle as well as the distance between the obstacle and the subject vehicle. An object detecting apparatus, which is based on the use of a radar and a stereo image sensor, is known as a technique for grasping, for example, the position, the size, and the distance as described above.
When the radar is used, it is possible to recognize a target (object provided as a detection objective) as a point of reflection of the electromagnetic wave. Accordingly, it is possible to acquire or obtain the position of the target. However, it is difficult to correctly acquire the edge of the target by means of the radar. On the other hand, it is possible to highly accurately acquire the edge of the target from an image picked up or photographed by the stereo image sensor. Thus, the object detecting apparatus as described above causes the fusion of the target information acquired by the radar and the target information acquired from the image picked up by the stereo image sensor. Accordingly, it is possible to improve the object detecting ability of the object detecting apparatus.
However, when the stereo image sensor is used as the image sensor, it is necessary to secure a relatively large space in order to install the stereo image sensor. Further, the cost is relatively expensive as well in order to realize the object detecting apparatus. Therefore, it is demanded that an object detecting apparatus, which has the function and the performance equivalent to those obtained when the stereo image sensor is used, is realized by using a monocular image sensor in place of the stereo image sensor.
Patent Document 1 discloses a vehicle obstacle recognizing apparatus which uses a millimeter wave radar and a monocular camera. The vehicle obstacle recognizing apparatus comprises an object information calculating means, an image processing means, and a vehicle information acquiring means. The object information calculating means calculates the object information including, for example, the relative lateral position and the relative distance with respect to the detection object from the output of the millimeter wave radar. The image processing means processes an image picked up or photographed by the monocular camera on the basis of the calculation result obtained by the object information calculating means. The vehicle obstacle recognizing apparatus judges the possibility of the detection object to behave as an obstacle on the basis of the outputs of at least the object information calculating means and the vehicle information acquiring means. Further, it is judged whether or not the output of the image processing means is effective to judge the obstacle, on the basis of the calculation result obtained by the object information calculating means. Only when the output of the image processing means is effective, the output of the image processing means is also used to judge the obstacle.
Patent Document 2 discloses an object detecting apparatus for acquiring image information and distance information from a camera and a radar. In the object detecting apparatus, the direction vector of the edge, the direction vector variance of the edge, the edge intensity, and the edge intensity variance are calculated from the image information. The type of an objective is judged on the basis of at least one of them and the distance with respect to the detection objective.